Improvement in hanging circular saws



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Letters Patent No, 81,661, dated September 1, 1868.

IMIROVEMENT 1N HANGING GIRGLAR SAWS. i

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TO ALL WHOM IT MAY CONCERN:

Be it known that'I, WILLIAM McDONALD, of Calais, inthe county of Washington, and State of Maine, haveV invented a. new and usefiil Improvement in 4Hanging or Securing Circular Saws to their Shafts; Vand I do hereby declare. that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in whieh- Figure 1 is a longitudinal section of a saw-shaft or arbor, with a saw secured upon it according to my invention, the saw being also in section, as indicated by the line :v x, fig. 2.

Figure vf?. is a detached side view cfa portion of the saw.

Figure 3 is a detached side view of a gauge or templet, used in carrying out my improvement.

i Similar letters of reference indicate corresponding parts.

This invention relates to an improvementdn hanging circular saws upon their arbors, and it consists in the combination of'two screw-pins with the saw, a xed and a movable collar, whereby the saw is held firmly upon the a'rbor, as will be hereinafter more fully described.

A represents a saw-shatter arbor, in which there is a fixed or permanent collar, B, the face-side of which is turned ofi` true, so as to be in a plane at right angles with the axis of the saw-shaft or arbor.

l C is a circular saw, which is provided with a central hole, to admit of the shaft or arbor passing through it.

D is a. loose cpllar,'which is fitted on the shaft or arbor at the outer side et" the saw, and E is a nut, which is fitted on-a screw-thread cut on the shaft. By screwing upthis nut, the saw C may be clamped between the two collars B D.

These partsare old, and'constitute a well-known means for securing circular saws on their shafts oriarbors.

My improvement is as follows: Y

Into the face-side of the permanent oriixed collar. B, I insert two pins or screws a a, which .are at equal distances from the saw-shaft or arbor, at opposite sides thereof, and in a line which passes transversely through the centre of the'saW-shaft or'nrbor. i

Through the saw C, there are made two` holes, at corresponding distances from its centre, and of such a diameter as to admit of the pins or-screws a 0L passing through them, corresponding holes being made in tli`e face ofthe loose collar D, to receive the lportions of the pins or screws which project through thc saw, as shown clearly in iig. 1. I

In -order to admit of the pins or screws a aand the holes in` the saw as well as those in the loose collar D, corresponding in position in every instance, 1 employ a'gauge ortemplet, F, shown clearlyrin g..3.

This gauge or templet, I prefer mhalring of a tempered or hardened-steel plate, having a central hole, t, corresponding in diameter withI the shaft or arbor-hole in the vcentre of the saw, and Vhaving two smaller` holes c, c, made in it at opposite sides of the hole Zagat distances corresponding with the distance of the pins or screws a tt from the shaft or arbor A. I

By means of this gauge or templet, the holes in the saw may beaccurately drilled, and all saws of a given I size Ior diameter, onintended for a certain-sized shaft or `arbor, litted properly on the latter, one saw being changed for another without any trouble or dilliculty whatever, dierent gauges or templets being employed `for dillerent-sized saws, or different-sized arbors. I

A sawyer may furnish a saw-maker `with a gauge or' templet, in ortlcr'to insure thevhole's being made correctly in the saw. i

By means of this improvement, a'sawwill be prevented from turning on` its arbor and unserewing the nut, and the latter does not require to be screwed upas tight as usual, and when thc face of the fixed or permanent collar B requires to be turned olf. i i

Havingthns described my invention, I claim as new, and desire to secure byv Letters Patent Thetixed collar B, provided with the series of pins a, adapted to pass'through the saw C and into the loose collar D, said sawand collar D beingclai'npedV firmly' to the iixed collar by the screw-nut E, as herein shown and described.

WM. McD ONALD.

Witnesses:

JOHN Blumen, J oHN MARTIN. 

